Preparation and Characterization of Nanoporous Sodium Carboxymethyl Cellulose Hydrogel Beads

A series of nanoporous sodium carboxymethyl cellulose (NaCMC) hydrogel beads were prepared using FeCl3 ionic crosslinker by changing polymer and crosslinker percentages (%). Characteristics of the hydrogels were investigated by gel content, swelling test, degradation test, Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR), Scanning Electron Microscope/Energy Dispersive X-ray Analysis (SEM/EDX), and Atomic Force Microscopy (AFM). Swelling experiments were studied by changing time, temperature, and pH. The swelling percentage (S%) regularly decreased with increasing the amounts of polymer and crosslinker, in contrast with gel content results. NaCMC hydrogels were found to be sensitive to pH variations. The degradation test showed that hydrogels had good stability and their degradation period varied from 30 to 36 days. According to SEM analysis, NaCMC hydrogels had mostly nanoporous structure. The average granule and pore sizes of the least swollen NaCMC-12 hydrogel were found to be 13.1 +/- 0.3nm and 82.1 +/- 3.2 nm. The elemental compositions of hydrogels were determined with EDX. The minimum average surface roughness (R-a) and root mean square roughness (R-ms) parameters were found to be 15.7 +/- 1.9nm and 20.3 +/- 2.2nm for NaCMC-12 hydrogels by AFM. Due to their good morphologies, stabilities, and swelling behaviors, NaCMC hydrogels can be suitable for biomaterial applications.